Ditto on the style points there!

Back to the comment on sling mounted spares, the sling on my .458 has a snap-closure pouch, not a pair of loops, holds four cartridges.

I practice shooting my SxS rifles with a pair of cartridges in my support hand, quickly reloading and shooting a second pair. Something I'd learned years ago while training with martial arms -- you'll do what you've been trained to do.
It's good to have a foundation of protocol to stand on when in stressful situations.

Cheers
Tinker